Regular Expression Tools

RegEx Libraries


  • Results update in real-time as you type.
  • Supports JavaScript & PHP/PCRE RegEx.
  • Roll over a match or expression for details.
  • Save & share expressions with others.
  • Use Tools to explore your results.
  • Browse the Reference for help & examples.
  • Undo & Redo with cmd-Z / Y in editors.
  • Search for & rate Community patterns.

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RE2 is a fast, safe, thread-friendly alternative to backtracking regular expression engines like those used in PCRE, Perl, and Python. It is a C++ library.

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TRE is a lightweight, robust, and efficient POSIX compliant regexp matching library with some exciting features such as approximate (fuzzy) matching.

The matching algorithm used in TRE uses linear worst-case time in the length of the text being searched, and quadratic worst-case time in the length of the used regular expression.

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